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Fix handling of inherited check constraints in ALTER COLUMN TYPE (again).

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The previous way of reconstructing check constraints was to do a separate
"ALTER TABLE ONLY tab ADD CONSTRAINT" for each table in an inheritance
hierarchy.  However, that way has no hope of reconstructing the check
constraints' own inheritance properties correctly, as pointed out in
bug #13779 from Jan Dirk Zijlstra.  What we should do instead is to do
a regular "ALTER TABLE", allowing recursion, at the topmost table that
has a particular constraint, and then suppress the work queue entries
for inherited instances of the constraint.

Annoyingly, we'd tried to fix this behavior before, in commit 5ed6546cf,
but we failed to notice that it wasn't reconstructing the pg_constraint
field values correctly.

As long as I'm touching pg_get_constraintdef_worker anyway, tweak it to
always schema-qualify the target table name; this seems like useful backup
to the protections installed by commit 5f173040.

In HEAD/9.5, get rid of get_constraint_relation_oids, which is now unused.
(I could alternatively have modified it to also return conislocal, but that
seemed like a pretty single-purpose API, so let's not pretend it has some
other use.)  It's unused in the back branches as well, but I left it in
place just in case some third-party code has decided to use it.

In HEAD/9.5, also rename pg_get_constraintdef_string to
pg_get_constraintdef_command, as the previous name did nothing to explain
what that entry point did differently from others (and its comment was
equally useless).  Again, that change doesn't seem like material for
back-patching.

I did a bit of re-pgindenting in tablecmds.c in HEAD/9.5, as well.

Otherwise, back-patch to all supported branches.
This commit is contained in:
Tom Lane 2015-11-20 14:55:28 -05:00
parent 9892cc2009
commit 47ea4614e9
4 changed files with 229 additions and 41 deletions
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37
src/backend/commands/tablecmds.c
View File

@ -3390,7 +3390,7 @@ ATExecCmd(List **wqueue, AlteredTableInfo *tab, Relation rel,
case AT_ReAddConstraint: /* Re-add pre-existing check
* constraint */
ATExecAddConstraint(wqueue, tab, rel, (Constraint *) cmd->def,
false, true, lockmode);
true, true, lockmode);
break;
case AT_AddIndexConstraint: /* ADD CONSTRAINT USING INDEX */
ATExecAddIndexConstraint(tab, rel, (IndexStmt *) cmd->def, lockmode);
@ -5764,13 +5764,6 @@ ATExecAddConstraint(List **wqueue, AlteredTableInfo *tab, Relation rel,
* AddRelationNewConstraints would normally assign different names to the
* child constraints. To fix that, we must capture the name assigned at
* the parent table and pass that down.
*
* When re-adding a previously existing constraint (during ALTER COLUMN TYPE),
* we don't need to recurse here, because recursion will be carried out at a
* higher level; the constraint name issue doesn't apply because the names
* have already been assigned and are just being re-used. We need a separate
* "is_readd" flag for that; just setting recurse=false would result in an
* error if there are child tables.
*/
static void
ATAddCheckConstraint(List **wqueue, AlteredTableInfo *tab, Relation rel,
@ -5798,7 +5791,7 @@ ATAddCheckConstraint(List **wqueue, AlteredTableInfo *tab, Relation rel,
*/
newcons = AddRelationNewConstraints(rel, NIL,
list_make1(copyObject(constr)),
recursing, /* allow_merge */
recursing | is_readd, /* allow_merge */
!recursing, /* is_local */
is_readd); /* is_internal */
@ -5842,10 +5835,8 @@ ATAddCheckConstraint(List **wqueue, AlteredTableInfo *tab, Relation rel,
/*
* If adding a NO INHERIT constraint, no need to find our children.
* Likewise, in a re-add operation, we don't need to recurse (that will be
* handled at higher levels).
*/
if (constr->is_no_inherit || is_readd)
if (constr->is_no_inherit)
return;
/*
@ -8204,10 +8195,30 @@ ATPostAlterTypeCleanup(List **wqueue, AlteredTableInfo *tab, LOCKMODE lockmode)
def_item, tab->changedConstraintDefs)
{
Oid oldId = lfirst_oid(oid_item);
HeapTuple tup;
Form_pg_constraint con;
Oid relid;
Oid confrelid;
bool conislocal;
tup = SearchSysCache1(CONSTROID, ObjectIdGetDatum(oldId));
if (!HeapTupleIsValid(tup)) /* should not happen */
elog(ERROR, "cache lookup failed for constraint %u", oldId);
con = (Form_pg_constraint) GETSTRUCT(tup);
relid = con->conrelid;
confrelid = con->confrelid;
conislocal = con->conislocal;
ReleaseSysCache(tup);
/*
* If the constraint is inherited (only), we don't want to inject a
* new definition here; it'll get recreated when ATAddCheckConstraint
* recurses from adding the parent table's constraint. But we had to
* carry the info this far so that we can drop the constraint below.
*/
if (!conislocal)
continue;
get_constraint_relation_oids(oldId, &relid, &confrelid);
ATPostAlterTypeParse(oldId, relid, confrelid,
(char *) lfirst(def_item),
wqueue, lockmode, tab->rewrite);

71
src/backend/utils/adt/ruleutils.c
View File

@ -420,6 +420,7 @@ static Node *processIndirection(Node *node, deparse_context *context,
static void printSubscripts(ArrayRef *aref, deparse_context *context);
static char *get_relation_name(Oid relid);
static char *generate_relation_name(Oid relid, List *namespaces);
static char *generate_qualified_relation_name(Oid relid);
static char *generate_function_name(Oid funcid, int nargs,
List *argnames, Oid *argtypes,
bool has_variadic, bool *use_variadic_p);
@ -1298,7 +1299,9 @@ pg_get_constraintdef_ext(PG_FUNCTION_ARGS)
prettyFlags)));
}
/* Internal version that returns a palloc'd C string; no pretty-printing */
/*
* Internal version that returns a full ALTER TABLE ... ADD CONSTRAINT command
*/
char *
pg_get_constraintdef_string(Oid constraintId)
{
@ -1347,10 +1350,16 @@ pg_get_constraintdef_worker(Oid constraintId, bool fullCommand,
initStringInfo(&buf);
if (fullCommand && OidIsValid(conForm->conrelid))
if (fullCommand)
{
appendStringInfo(&buf, "ALTER TABLE ONLY %s ADD CONSTRAINT %s ",
generate_relation_name(conForm->conrelid, NIL),
/*
* Currently, callers want ALTER TABLE (without ONLY) for CHECK
* constraints, and other types of constraints don't inherit anyway so
* it doesn't matter whether we say ONLY or not. Someday we might
* need to let callers specify whether to put ONLY in the command.
*/
appendStringInfo(&buf, "ALTER TABLE %s ADD CONSTRAINT %s ",
generate_qualified_relation_name(conForm->conrelid),
quote_identifier(NameStr(conForm->conname)));
}
@ -1874,28 +1883,9 @@ pg_get_serial_sequence(PG_FUNCTION_ARGS)
if (OidIsValid(sequenceId))
{
HeapTuple classtup;
Form_pg_class classtuple;
char *nspname;
char *result;
/* Get the sequence's pg_class entry */
classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(sequenceId));
if (!HeapTupleIsValid(classtup))
elog(ERROR, "cache lookup failed for relation %u", sequenceId);
classtuple = (Form_pg_class) GETSTRUCT(classtup);
/* Get the namespace */
nspname = get_namespace_name(classtuple->relnamespace);
if (!nspname)
elog(ERROR, "cache lookup failed for namespace %u",
classtuple->relnamespace);
/* And construct the result string */
result = quote_qualified_identifier(nspname,
NameStr(classtuple->relname));
ReleaseSysCache(classtup);
result = generate_qualified_relation_name(sequenceId);
PG_RETURN_TEXT_P(string_to_text(result));
}
@ -9138,6 +9128,39 @@ generate_relation_name(Oid relid, List *namespaces)
return result;
}
/*
* generate_qualified_relation_name
* Compute the name to display for a relation specified by OID
*
* As above, but unconditionally schema-qualify the name.
*/
static char *
generate_qualified_relation_name(Oid relid)
{
HeapTuple tp;
Form_pg_class reltup;
char *relname;
char *nspname;
char *result;
tp = SearchSysCache1(RELOID, ObjectIdGetDatum(relid));
if (!HeapTupleIsValid(tp))
elog(ERROR, "cache lookup failed for relation %u", relid);
reltup = (Form_pg_class) GETSTRUCT(tp);
relname = NameStr(reltup->relname);
nspname = get_namespace_name(reltup->relnamespace);
if (!nspname)
elog(ERROR, "cache lookup failed for namespace %u",
reltup->relnamespace);
result = quote_qualified_identifier(nspname, relname);
ReleaseSysCache(tp);
return result;
}
/*
* generate_function_name
* Compute the name to display for a function specified by OID,

130
src/test/regress/expected/alter_table.out
View File

@ -1805,16 +1805,125 @@ where oid = 'test_storage'::regclass;
t
(1 row)
-- ALTER TYPE with a check constraint and a child table (bug before Nov 2012)
CREATE TABLE test_inh_check (a float check (a > 10.2));
-- ALTER COLUMN TYPE with a check constraint and a child table (bug #13779)
CREATE TABLE test_inh_check (a float check (a > 10.2), b float);
CREATE TABLE test_inh_check_child() INHERITS(test_inh_check);
\d test_inh_check
Table "public.test_inh_check"
Column | Type | Modifiers
--------+------------------+-----------
a | double precision |
b | double precision |
Check constraints:
"test_inh_check_a_check" CHECK (a > 10.2::double precision)
Number of child tables: 1 (Use \d+ to list them.)
\d test_inh_check_child
Table "public.test_inh_check_child"
Column | Type | Modifiers
--------+------------------+-----------
a | double precision |
b | double precision |
Check constraints:
"test_inh_check_a_check" CHECK (a > 10.2::double precision)
Inherits: test_inh_check
select relname, conname, coninhcount, conislocal, connoinherit
from pg_constraint c, pg_class r
where relname like 'test_inh_check%' and c.conrelid = r.oid
order by 1, 2;
relname | conname | coninhcount | conislocal | connoinherit
----------------------+------------------------+-------------+------------+--------------
test_inh_check | test_inh_check_a_check | 0 | t | f
test_inh_check_child | test_inh_check_a_check | 1 | f | f
(2 rows)
ALTER TABLE test_inh_check ALTER COLUMN a TYPE numeric;
\d test_inh_check
Table "public.test_inh_check"
Column | Type | Modifiers
--------+------------------+-----------
a | numeric |
b | double precision |
Check constraints:
"test_inh_check_a_check" CHECK (a::double precision > 10.2::double precision)
Number of child tables: 1 (Use \d+ to list them.)
\d test_inh_check_child
Table "public.test_inh_check_child"
Column | Type | Modifiers
--------+------------------+-----------
a | numeric |
b | double precision |
Check constraints:
"test_inh_check_a_check" CHECK (a::double precision > 10.2::double precision)
Inherits: test_inh_check
select relname, conname, coninhcount, conislocal, connoinherit
from pg_constraint c, pg_class r
where relname like 'test_inh_check%' and c.conrelid = r.oid
order by 1, 2;
relname | conname | coninhcount | conislocal | connoinherit
----------------------+------------------------+-------------+------------+--------------
test_inh_check | test_inh_check_a_check | 0 | t | f
test_inh_check_child | test_inh_check_a_check | 1 | f | f
(2 rows)
-- also try noinherit, local, and local+inherited cases
ALTER TABLE test_inh_check ADD CONSTRAINT bnoinherit CHECK (b > 100) NO INHERIT;
ALTER TABLE test_inh_check_child ADD CONSTRAINT blocal CHECK (b < 1000);
ALTER TABLE test_inh_check_child ADD CONSTRAINT bmerged CHECK (b > 1);
ALTER TABLE test_inh_check ADD CONSTRAINT bmerged CHECK (b > 1);
NOTICE: merging constraint "bmerged" with inherited definition
\d test_inh_check
Table "public.test_inh_check"
Column | Type | Modifiers
--------+------------------+-----------
a | numeric |
b | double precision |
Check constraints:
"bmerged" CHECK (b > 1::double precision)
"bnoinherit" CHECK (b > 100::double precision) NO INHERIT
"test_inh_check_a_check" CHECK (a::double precision > 10.2::double precision)
Number of child tables: 1 (Use \d+ to list them.)
\d test_inh_check_child
Table "public.test_inh_check_child"
Column | Type | Modifiers
--------+------------------+-----------
a | numeric |
b | double precision |
Check constraints:
"blocal" CHECK (b < 1000::double precision)
"bmerged" CHECK (b > 1::double precision)
"test_inh_check_a_check" CHECK (a::double precision > 10.2::double precision)
Inherits: test_inh_check
select relname, conname, coninhcount, conislocal, connoinherit
from pg_constraint c, pg_class r
where relname like 'test_inh_check%' and c.conrelid = r.oid
order by 1, 2;
relname | conname | coninhcount | conislocal | connoinherit
----------------------+------------------------+-------------+------------+--------------
test_inh_check | bmerged | 0 | t | f
test_inh_check | bnoinherit | 0 | t | t
test_inh_check | test_inh_check_a_check | 0 | t | f
test_inh_check_child | blocal | 0 | t | f
test_inh_check_child | bmerged | 1 | t | f
test_inh_check_child | test_inh_check_a_check | 1 | f | f
(6 rows)
ALTER TABLE test_inh_check ALTER COLUMN b TYPE numeric;
NOTICE: merging constraint "bmerged" with inherited definition
\d test_inh_check
Table "public.test_inh_check"
Column | Type | Modifiers
--------+---------+-----------
a | numeric |
b | numeric |
Check constraints:
"bmerged" CHECK (b::double precision > 1::double precision)
"bnoinherit" CHECK (b::double precision > 100::double precision) NO INHERIT
"test_inh_check_a_check" CHECK (a::double precision > 10.2::double precision)
Number of child tables: 1 (Use \d+ to list them.)
@ -1823,10 +1932,27 @@ Table "public.test_inh_check_child"
Column | Type | Modifiers
--------+---------+-----------
a | numeric |
b | numeric |
Check constraints:
"blocal" CHECK (b::double precision < 1000::double precision)
"bmerged" CHECK (b::double precision > 1::double precision)
"test_inh_check_a_check" CHECK (a::double precision > 10.2::double precision)
Inherits: test_inh_check
select relname, conname, coninhcount, conislocal, connoinherit
from pg_constraint c, pg_class r
where relname like 'test_inh_check%' and c.conrelid = r.oid
order by 1, 2;
relname | conname | coninhcount | conislocal | connoinherit
----------------------+------------------------+-------------+------------+--------------
test_inh_check | bmerged | 0 | t | f
test_inh_check | bnoinherit | 0 | t | t
test_inh_check | test_inh_check_a_check | 0 | t | f
test_inh_check_child | blocal | 0 | t | f
test_inh_check_child | bmerged | 1 | t | f
test_inh_check_child | test_inh_check_a_check | 1 | f | f
(6 rows)
-- check for rollback of ANALYZE corrupting table property flags (bug #11638)
CREATE TABLE check_fk_presence_1 (id int PRIMARY KEY, t text);
CREATE TABLE check_fk_presence_2 (id int REFERENCES check_fk_presence_1, t text);

32
src/test/regress/sql/alter_table.sql
View File

@ -1252,12 +1252,40 @@ select reltoastrelid <> 0 as has_toast_table
from pg_class
where oid = 'test_storage'::regclass;
-- ALTER TYPE with a check constraint and a child table (bug before Nov 2012)
CREATE TABLE test_inh_check (a float check (a > 10.2));
-- ALTER COLUMN TYPE with a check constraint and a child table (bug #13779)
CREATE TABLE test_inh_check (a float check (a > 10.2), b float);
CREATE TABLE test_inh_check_child() INHERITS(test_inh_check);
\d test_inh_check
\d test_inh_check_child
select relname, conname, coninhcount, conislocal, connoinherit
from pg_constraint c, pg_class r
where relname like 'test_inh_check%' and c.conrelid = r.oid
order by 1, 2;
ALTER TABLE test_inh_check ALTER COLUMN a TYPE numeric;
\d test_inh_check
\d test_inh_check_child
select relname, conname, coninhcount, conislocal, connoinherit
from pg_constraint c, pg_class r
where relname like 'test_inh_check%' and c.conrelid = r.oid
order by 1, 2;
-- also try noinherit, local, and local+inherited cases
ALTER TABLE test_inh_check ADD CONSTRAINT bnoinherit CHECK (b > 100) NO INHERIT;
ALTER TABLE test_inh_check_child ADD CONSTRAINT blocal CHECK (b < 1000);
ALTER TABLE test_inh_check_child ADD CONSTRAINT bmerged CHECK (b > 1);
ALTER TABLE test_inh_check ADD CONSTRAINT bmerged CHECK (b > 1);
\d test_inh_check
\d test_inh_check_child
select relname, conname, coninhcount, conislocal, connoinherit
from pg_constraint c, pg_class r
where relname like 'test_inh_check%' and c.conrelid = r.oid
order by 1, 2;
ALTER TABLE test_inh_check ALTER COLUMN b TYPE numeric;
\d test_inh_check
\d test_inh_check_child
select relname, conname, coninhcount, conislocal, connoinherit
from pg_constraint c, pg_class r
where relname like 'test_inh_check%' and c.conrelid = r.oid
order by 1, 2;
-- check for rollback of ANALYZE corrupting table property flags (bug #11638)
CREATE TABLE check_fk_presence_1 (id int PRIMARY KEY, t text);